Removal of sulfate from aqueous solution by magnetic chitosan microspheres

Abstract

a b s t r a c tThe magnetic chitosan microspheres (Fe 3 O 4 /CS) were prepared by inverse suspension cross-linking and characterized by scanning electron microscope, optical micrographs, Fourier transform infrared spectrophotometer, and X-ray diffraction. They were employed as the adsorbents for the removal of sulfate from the aqueous solutions in the batch system. The magnetic material (Fe 3 O 4 ) used in the preparation of the magnetic chitosan microspheres was prepared by precipitation from FeCl 2 and FeCl 3 solutions in the basic medium. The experimental results showed that Fe 3 O 4 /CS was an excellent adsorbent for the removal of sulfate with an adsorption capacity of 256.41 mg g -1 . Equilibrium isotherm study showed a good agreement with the Langmuir isotherm equation for the monolayer adsorption process, while the adsorption process can be well described by the second-order kinetic model and the Dubinin-Radushkevich isotherm further confirmed the presence of physical adsorption forces.

Sequestration of Sulfate Anions from Groundwater by Biopolymer-Metal Composite Materials

“…In freshwater species, sulfate can be lethal at elevated concentrations due to osmoregulatory stress [7,8]. The latter occurs upon bacterial reduction of sulfate under anaerobic conditions to produce hydrogen sulfide (H 2 S) [9] The weak acid properties of aqueous hydrogen sulfide solution can be [58] This study focuses on the synthesis and characterization of binary (two-component) and ternary (three-component) composite materials that contain animal and/or plant biopolymers (chitosan and alginate) as building blocks in conjunction with copper (II) species. The unique contribution of Cu(II) species to the formation the ternary biopolymer composites yield enhanced adsorption capacity of sulfate anions for laboratory and groundwater samples will be demonstrated herein.…”